Bore hole exploring apparatus



April 16, '1940. J. w. MILLINGTON Er A1. 197.1571

BORE EXPLORING AKPPARATUS I I Filed oct. s, 193e 2 sheets-sneer 1 s ff? 2,197,511 i y noaa nona mncnmo APPARATUS Application October 3,

This invention relates to bore hole exploring apparatus, which term is used generically in this case to indicate generally apparatus for making measurements within bore holes such as, for

5 example, electrical logging apparatus or well surveying apparatus. The invention is concerned with the proper control in accordance with depth of apparatus located within a casing. which is adapted to be moved through a bore hole and which is closed to withstand the pressures encountered in the hole.

In the case of well surveying apparatus or electrical logging apparatus or the like, it is genern ally desirable to make records within the bore hole of the indications of various pieces of apparatus which are passing through the hole'. The records thus made should be correlated with the depth at which they are made, and to effectthis result various arrangements have been used and numerous proposals have been made, the latter including proposals requiring motion to be transmitted mechanically through the casing, a proposal impracticable of achievement because of the enormous pressures encountered in a hole. 25 One of the commonest methods of correlating the records with depth comprises recording the time When the records are made and simultaneously noting the depths reached at various times. From this data the depths at which the records 30 are made may be determined. It has also been proposed to transmit signals to the recording apparatus when various depths are reached so as to correlate the records with depth. Electrical connections through a casing capable of with- 35 standing bore hole pressures may be readily made. In accordance with the present invention, the recording apparatus within the bore hole is operated in proportion to the depths which are reached by it, by utilization of an electrical connection between a device responsive to the length of cable played out at the surface and apparatus within the casing which is being lowered so that .the latter is controlled by the former. Specically, in accordance with the present invention, the records are made upon a continuous strip, preferably in the form of a photographic film, the feed of which strip is controlled by the feed of the cable at the surface.

The broad object of the invention is the attainment of the general results indicated above. This object and subsidiary objects, relating particularly todetails of construction and operation, will be apparent from the following description, read in conjunction with the accompanying drawings, in which:

tai)

193s, serial No. 232,969

(ci. 23a-1.5)

Figure 1 is a Wiring diagram illustrating the synchronizing means between the surface apparatus and that within the casing;

Figure 2 is a wiring diagram illustrating certain apparatus within the casing for the purpose 5 of proper control of exposures or the like;

Figure 3 is a wiring diagram showing the application of the invention to an electrical logging apparatus of the high frequency type;

Figure 4 is a vertical sectional View showing a 10 type of well surveying apparatus to which the invention is applied; and

Figure 5 is a diagrammatic view illustrating an alternative form of motor adapted to be operated in synchronism with apparatus at the surface.

Fundamentally, the improved synchronizing arrangement comprises a motor within a casing along with other apparatus adapted for recording purposes, which motor is connected to the surface so as to be operated in synchronism with means 20 which measures the depth of the apparatus within the bore hole. The invention is concerned in one of its more specific aspects with the attainment of proper synchronism consistent with varying speeds of lowering the cable and, furthermore, with the use of. a cable carrying a minimum number of conductors. In accordance with the invention, a cable carrying a single conductor may be used, the return connection being made through the ground, though, as illustrated, a two-conductor cable is somewhat preferable. Cables containing one or two conductors and properly armored for use within bore holes are relatively inexpensive, but the expense increases rapidly with the number of conductors, and hence it is desirable to keep the number of conductors necessary at a minimum. For this purpose, there has been devised in accordance with the present invention, an apparatus operating through the use of direct current which will maintain synchronism despite varying speeds or interruption of the lowering of the cable.

Referring nrst to Figure 1, there is indicated at 2 ,the reel on which the cable d, supporting the apparatus within the bore hole, is wound. This reel 2 is provided with slip rings 6 and 8 connected to the ends of the conductors l0 and l2, which are located within the cable. The cable, as usualVpasses over a supporting pulley l, and below this pulley the cable is engaged by 60 means of a cable measuring device, conventionally illustrated at I6, which device may be of the usual form. Such devices, in order to give accurate indications of the depth of the apparatus which the cable supports, must engage the dfi titi

cated below.

cable on its vertical run' where it will he iully stretched so that the measuring taires account of the stretch of the cable and gives accurate indications.

The measuring apparatus l@ is connected, by means or" elements lil, which may include stepup gearing, to a commutator comprising segments 2d with which engage brushes '22v connected to the poles of a battery 2Q and with which also engage brushes E@ connected to brushes engaging the slip rings (i and l. With these connections asillustrated the conductors lil and l2 have imparted to them a 'voltage which alternates at a rate depending upon the rate of revolution of the commutator 2li. The number of alternations bears a direct relationship to the depth of the apparatus supported by the cable ll.

The apparatus supported by the cable l may be, for example, a well surveying instrument, e1ectrical logging apparatus, temperature measuring apparatus, or the like. Within the casing oi' this apparatus, examples of which will be later described, there is located va motor which is preierably of the type illustrated in the lower 'portion of Figure l. This motor comprises a shaft di? carrying slip rings @il and il@ which are respec tively engaged by brushes connected to the con ductors lli and l2. The slip rings are connected tothe ends of an armature winding 32 carried by a two-pole armature indicated at 3Q- secured to the motor shaft.

The stator of the motor is provided with poles the windings of which are indicated at 313 and which are so arranged as to be alternately north and south. The pole windings, which are joined and grounded at one end oi eachas at G, are connected at their other ends to stationary conducting segments 30 with which 'there engage brushes lil mounted on the motor shaft il@ through the inediurn of arm and connected to one pole ci a battery ll the other pole ci. which is grounded. Ey the arrangement oi7 the hrushes E@ as illustrated in Figure l it ywill be obvious only four of the poles are energized simultaneously. As a consequence of this, assuming, icr example, that the armature is at rest and at that time polarized as indicated in Figure l so as to occupy a Vertical position in aliginnent with the vertically related pair of poles, upon change of the direction of current through its winding 3250 that its upper pole becomes north, it will rotate clockwise because only the poles in the clockwise direction are energized at the time. As it rotates, it carries the brushes lll with it to effect energization of the next. poles ln the di-= rection of advance of its rotation. As a conse `quence of this arrangement, the rotation of the armature is always in the same direction. Due regard must, oi 'course,.be had to the manipulation of the cable the motion of which should not be reversed unless account of that fact is taken.

The above arrangement for insuring that rotation occurs in only one direction makes it possible to use either a sngleconductor cable with ground return or a two-conductor cable. By use of a triple pole armature and three connections to the surface, (following the disclosure of the patent to Ford 1,153,210), it is possible to insure rotation in a predetermined direction without thev use of brushes such as I or 'any other arrangement of unusual character, as indi- However, it is preferred to use an arrangement of the type indicated to avoidmultipllcity of conductors within the cable.

condition occurs when the relay is enero i time.

arcata-fi l'n the event that recording is accomplished by means oi a stylus or the lilte, the motor, which been just described, may be directly to a record strip with the result that the motion oi the strip will be directly proportional to the depth the apparatus. ln malette photographic records, however, the production of over exposure must "ce taken into account so that obviously seine means must be provided to insure that, while the motion oi' the film is proportional to the depth, over exposure or improper. exposures lwill not result if the lowering is slowed down or interrupted for substantial periods or" time. 'lo adapt the synchronizing apparatus to photographic recording, there may be utilized the auxlliary control apparatus indicated in Figure lin Figure 2 there is indicated at tdthe shaft of the motor previously described, or, alternatively, this may be tal-cen to indicate a shaft geared thereto, but at any rate operating in synchronisin wit the motor shaft. rihis shat carries a cara member 3@ adapted to engage a' iollower E inalring contact with a point connected to a line lili extending from a battery dll, to the other pole of which there ls connected a line it relay Gli is provided with a pair oi armatures [32 and i/'Vhen relay is deenergized, the contact oi is open and that at @C is closed. r'he reverse Connected between the armature till the iine 53 is a motor GG which, preferably through reduction gearing, is arranged to drive conductor rings and "Nl, the former of which is provided with brealr indicated at and the latter ci which is provided with a hreaii: at itt These breaks are so arranged as .e opposite the respective brushes lil and 'lil the The brush which is to raalte contact, with the ring is connected between the inotor and the armature Wr, while the brush adapted to maire contact with the lll, is connected to the side of the relay coil @il which connected to the armature the other side ci' the relay coil being connected to the line @hunted across the motor soas to energized whenever the motor is energized may be a second relay Gd, adapted to close a contact inn dicated at Si. when the timing apparatus is adapted to be used forY indirect control oi another circuit. Such operation will he described hereafter.

The wiring arrangement of Figure 2 is designed to insure proper exposure oi a photographic record iilrn. The motor @it may drive through suitable reduction gearing the film on which some record is to be made. Assuming that the various parts are in the conditions indicated in Figure 2, each revolution of the shaft I8 will eflect a closure for a limited period of the contacts lli and When any such closure takes place, the motor t@ will be energized and will start torun. Very shortly after the motor starts to run, the brushes l2 and l5 will make contact with their vrespective rings 68 and 14 which are connected to the line B. The brush 12 provides an auxiliary energization of the'motor 66 independent of v l of the brushes l2 and 18.

aleman with the contact at 52-56 provides a second energizing connection for the coil 60.

After these events, the motor 66 continues to run, causing advance of the film and, as later described, possibly controlling some other events in the making of a proper exposure. Such events may be controlled through the relay B which, as noted above, is energized simultaneously with the motor 66.

The motor 66 should be so arranged that it will cause a complete revolution of the rings 68 and 'I before the shaft 8 can make a sufficient portion of a revolution to produce another closure of the contacts 52 and 54. In normal operation. the contact between 52 and 54 will be broken by reason of the continued lowering of the apparatus before the breaks T0 and 16 return to the position Upon disengagement of 52 and 5d, no changes in the operation of the motor 66 or relay 60 occur, the former remaining energized through the brush 12 and the latter through the brush 78. On the other hand, when the gaps '|0 and 16 come around breaking the contacts between the slip rings and their brushes, the motor 66 will stop and the relay 60 will be deenergized, dropping both the armatures 62 and 64. Accordingly, the apparatus will be ready for another cycle upon the next engagement of the contacts 52 and 54 under the action of cam 50.

On the other hand, let it be assumed that upon causing contact between 52 and 54, the lowering was stopped before the contact was broken. In such case, when the rings 68 and 14have made one revolution, the motor 66 will stop, but the relay 60 will remain energized because of the closed condition of 62, which will remain so despite the disengagement of brush 18 from ring 14 because of the closure of the shunting circuit at 52 and 54. At the same time, however, the armature 64 will be raised so that the motor will stop despite the closure at 52-5li. Thus, it is insured that the motor will not be restarted until the opening of the circuit at 52-54 followed by-its subsequent closure.

In other words, with the apparatus of Figure 2, the feed of the film is intermittent and exposure may be controlled through the relay 80 so that only for a limited period in each cycle of operation is there any exposure made.

To make clearer the specic application of the invention, reference may be made to Figure 3, which discloses a logging apparatus of a high frequency type in which the record is made in the form of a variable density trace which indicates the nature of the formations traversed by the apparatus. This type of apparatus is disclosed in detail in Bazzoni and Razek application Serial No, 222,609, tiled August 2, 1938, to which application reference may be made for details. So far as the present case is concerned, it willsuflice to point out that the apparatus comprises a vacuum tube 84 in an oscillator circuit controlled by a crystal 86. The tank circuit comprises a condenser 88 and a coupling coil 90, and in addition, an exploring coil 92 which is located outside the casing of the apparatus and serves to establish an electromagnetic field in the formations which are traversed. Coupled to the coil 90 is a wave meter circuit comprising coils 94 and 98 and a condenser 96. To the coil 98 is coupled a lamp |00 in a circuit which includes the contacts 62 of the relay 80 previously described and illustrated in Figure 2. The lamp |00 through the medium of an optical system indicated at |02 is designed to project a spot of light upon a film |06 which is adapted to be advanced through suitable reduction gearing 67 by means of the motor 66, which has been described.

Additionally there may be provided a lamp |06 designed to project on the film a spot by means-of a lens |08, which lamp is energized by a battery I0 in circuit with a brush I4, which bears upon an insulating ring provided over a short angular portion of its circumference with a conductor I2 connected to the side of the lamp opposite the battery I0. This contact disc may be driven through suitable reduction gearing from the shaft 158 so that contact is made at. the occurrence of predetermined depth intervals as indicated by the motor of Figure l.

With the above type of apparatus it is desirable Y to secure readings at as closely spaced intervals as possible. For example, let it be assumed that an exposure is to be made every foot, in which case overlapping of the spots of light produced by the lamp |00 for successive records should occur. In such case, the gearing of the various parts should be such that contact between 52 and 54 will occur at every foot of lowering of the apparatus. The motor 66 in such case should be so arranged as to`cause its rings 68 and 1B to make a complete revolution in a time appreciably less than the minimum time of lowering of the apparatus through a distance of one foot. The advance of the film may be scaled through the reduction gearing 61 so that, for example, the advance might be, say, a twenty-fifth of an inch per foot. Under such conditions, during continuous lowering of the apparatus the relay contacts 82 would be closed for a predetermined period depending on the speed 'of the motor 66 for each foot of lowering, and it will be obvious that the exposure at each foot interval will be totally independent of the speed of lowering of the apparatus or even of the complete cessation of lowering, whether or not during such cessation contact between 52 and 54 is or is not made. For ease in reference on the iinal film, the lamp |06 may be caused to ash to mark intervals of, say, one hundred feet. Whether or not the markings produced by the lamp |00 after development overlap or do not overlap, their variable density may be made the measure of the effect of the strata traversed by the instrument upon the eld produced by the coil 92. It will be obvious that the mere fact that the trace is intermittently made will not aiect 'A the usefulness of .the record.

Whereas in the case of a logging apparatus such as just described it is desirable to produce exposures at relatively small depth intervals, a somewhat different problem arises in connection with the type of well surveying instrument illustrated in Figure 4, which is fully described in Williston et al. Patent 1,960,038, dated May 22, 1934. As described in that patent, the well surveying instrument comprises a housing ||6 adapted to be received in a protettive oasing. Within the housing ||6 there is a camera indicated at 20, adapted to be driven by a motor |26 which may be the same as that at 66 in Figure 2 in the event that the present invention is applied to such well surveying apparatus. Lamps |26 and |28 serve to illuminate the instruments which are photographed, which include a. gyrascope indicated at |30 and a level indicated at |32. The apparatus of the Williston et al. patent includes a watch which is photographed with the other instruments to give indications of depth. In the use of the present invention this watch may be eliminated. Included within the well surveying apparatus are the devices illustrated in l and 2. if the camera motor i213 is driven in the fashion oi the motor of liigure 2,

it will effect advance of the film and then, while the Film is at rest, illumination of the to eeposure to ricade. In the application of the invention to this apparatus it he desirable te provide that exposure should. be made only at intervals of, say, fty or one hundred feet. gearing may, therefore, be provided either between the wire measuring device and its cemmutator, or between the motor and the cam member C1@ which provides for intermittent operation of the carriera driving motor. 'in the case of this apparatus the relay may be omitted unless some auxiliary control is desired for seme part. The utilization or the arrangement indicated will insure that an exposure is made at every predetermined depth without, however, possibility oi over exposure or the possibility of Athere being made a number of exposures 'at the same depth.

lt may be observed that the recordingmay take place during both lowering and raising oi the apparatus inasmuch as the commutator, unless disconnected at the surface, will produce the alternations of current ow to the controlling motor during movements in both directions. Under such circumstances, there should be kept a proper log at the surface indicating whether or not change of direction has taken place and at Whatdepths such change has occurred.

Instead of utilizing the type of' motor indicated in Figure 1, there may be used a mechanical locate asymmetrically with respect to the polesv the outward projecting poles |42 of the armature. With the arrangement as illustrated in Figure 5, reversal .of current flow through the armature winding will always advance the armature in a clockwise direction. since it more closely approaches the poles in the clockwise .direction than the poles in the counter-clockwise direction.

It will be clear that various changes may 'ce made in the embodiment oi! the invention withlengthwise movementsoi the supporting means I,

for eaiecting mover: ents ci said motor proportion to the movements ci the supporting means within the hole.

2. liore hole exploring means comprising apparatus adapted to be lowered Within a bore hole, said apparatus including e motor and recording means operated by the motor, supporting means for said apparatus comprising an electrically conn ducting cableand electrical control means el ated in accordance with the lengthwise more ments of said cable for effecting, by electrical transmission through the cable, movem said motor in proportion to said. cable mo c. .--rl-ts.

3. Bore hole exploring means comprising apparatus adapted to be lowered within a 'bore hole, said apparatus including a motor and recording means operated by the motor, supporting means for said apparatus comprising an electrically conducting cable, adevice movable proportionally to the lengthwise movements of said cable, and means controlled by the device and operating by electrical transmission through the cableto effect movements of said motor in proportion to said cable movements. y

4. Bore hole exploring means comprising apparatus adapted to be lowered within a bore hole, said apparatus including a shaft and recording means operated by the shaft, supporting means for said apparatus comprising an electrically con ducting cable, a device movable proportionally to the lengthwise movements of said cable, and means controlled by the device and operating by electrical transmission through the cable to effect movements of said shaft in proportion to said cable movements.

5. Bore hole exploring means comprising apparatus adapted to be lowered within a bore hole, said apparatus including an electric motor and A recording means operated by the motor, supporting means for said apparatus. and means for effecting movements of said motor in proportion to movements of. saidA apparatus lengthwise of the hole.

JOHN W. llfiIIilllING'ION.v

WILLIAM T. EVANS. 

